Sheet feeding mechanism for printing presses



July 17, 1951 w. w. DAVIDSON SHEET FEEDING MECHANISM FOR PRINTING PRESSES Filed Dec. :1, 1948 6 Sheets-Sheet l fra /enfor- ZZ/ardlbuz'aaom.

W. W. DAVIDSON SHEET FEEDING MECHANISM FOR PRINTING PRESSES July 17, 1951 6 Sheets-Sheet 2 Filed Dec. 31, 1948 MW/Mw y 7, 1951 w. w. DAVIDSON 2,561,015

SHEET FEEDING MECHANISM FOR PRINTING PRESSES 6 Sheets-Sheet 5 Filed Dec. 31, 1948 1 wenZZarx- L I g m M/M July 17, 1951 w. w. DAVIDSON SHEET FEEDING MECHANISM FOR PRINTING PREssEs Filed Dec. 31, 1948 6 Sheets-Sheet 4 July 17, 1951 Filed Dec. 31, 1948 W. W. DAVIDSON SHEET FEEDING MECHANISJ FOR PRINTING PRESSES 6 Sheets-Sheet 5 W. W. DAVIDSON SHEET FEEDING MECHANISM FOR PRINTING PRESSES July 17, 1951 6 Sheets-$heet 6 Ill/11,, vllllzll. 'IIIIIIIIIII Filed 'Dec. 31, 1948 Patented July 17, 1951 SHEET FEEDING MECHANISM FOR PRINTING PRESSES William Ward Davidson, Evanston, Ill., asslgnor,

by mesne assignments, to Davidson Corporation, a corporation of Illinois Application December 31, 1948, Serial No. 68,458

6 Claims. (Cl. 271-53) My present invention relates to an improvement in a printing press, and more particularly to sheet registration and feeding means for feeding sheets to be printed to the printing couple of the press.

In certain of my previous patents, among which Patent No. 2,387,750, dated October 30, 1945, is an example, I have shown and described a printing press adapted for either offset or letter press printing, comprising a small cylinder and a large cylinder, with the latter being preferably twice the diameter of the small cylinder. The small cylinder, as is well known in the type of press referred to, for purposes of offset printing, carries a suitable transfer blanket and the large cylinder is made up of plate and platen segments. The arrangement is such that for one revolution of the plate and platen cylinder, the small or blanket cylinder revolves twice. In such rotation of the cylinders, the plate carried by the plate segment transfers an ink image to the blanket of the blanket cylinder and the ink image on the blanket cylinder is transferred to a sheet to be printed when fed in appropriately timed relation between the platen surface of the platen segment and the blanket cylinder.

- The press may be readily converted for letter press printing by removing the plate segment from the large cylinder, substituting a direct letter printing plate for the platen segment, and providing the small cylinder with an appropriate platen surface. The dampening mechanism used for offset printing is, of course, caused to be rendered inoperative, and sheets to be printed are caused to be fed between the direct letter plate of the large cylinder and the platen surface of the small cylinder.

It has been proposed in a press of the above type to arrange the small or blanket cylinder above the large, or plate and platen cylinder, and to provide the plate and platen cylinder with sheet gripping means at the leading edge of the platen segment. Such an arrangement is particularly adapted for the hand feeding of sheets to the press, and disposes the blanket cylinder in convenient position for cleaning purposes.

In my copending application, Serial No. 777,- 245, filed October 1, 1947, I have shown a press arranged, as last aforesaid, for the purposes noted, and it is an object of my present invention to provide in a press so arranged of sheet registering and feeding means, enabling the more convenient manual feeding of sheets to the press.

It is a further object of my invention to provide a printing press of the character noted hav ng 2 sheet registering and feeding means providing for the convenient hand feeding of sheets to be printed with the press running continuously.

A further object is to provide sheet feeding means having sheet registration means, such as stop fingers, against which a sheet may be manually abutted during the cycle of operation of the press when the ink image is being transferred to the blanket by the plate carried by the plate segment. and with the feeding means being operable to feed the sheet so positioned to the gripper means of the large cylinder in appropriate timed relation for printing by the press.

In a press having a cycle of operation as above described, ample opportunity is provided for the intermittent hand feeding of successive sheets to the press following printing of the preceding sheet and conditioning of the press for printing of a succeeding sheet. By the provision of registration means, such as stop fingers against which the operator may feed the sheet, and arranging feeding means operable in appropriate timed sequence with the press to deliver the sheet from its registered position to the printing couple, presses of the character indicated may be greatly simplified enabling their economic manufacture and adaptation to a wide variety of printing purposes not previously feasible with earlier forms of press of this general type.

The above and other objects, advantages and features of my invention will appear from the following detailed description of a preferred embodiment of my invention.

Now in order to acquaint those skilled in the art with the manner of constructing and utilizing printing presses constructed in accordance with the principles of my present invention, I shall describe, in connection with the accompanying drawings, a preferred embodiment of my invention.

In the drawings:

Figure 1 is a side elevational view of a printing press of a type to which my present invention is applicable;

Figure 2 is a longitudinal vertical sectional view of the upper portion of the printing press of the type of Figure 1 with my present invention embodied therein, taken substantially along the line 2-2 of Figure 5 looking in the direction indicated by the arrows, and showing the position of the parts of the press just prior to the feeding of a sheet to the press;

Figure 3 is a view like Figure 2 but showing the positions of the parts of the press when a sheet is being fed to the press;

Figure 4 is a plan view of the press of Figures 2 and 3, but with the blanket cylinder omitted for purposes of clarity in showing the structure therebelow;

Figure is an end elevational view of the press as viewed from the righthand side of Figures 2 and 3; and

Figure 6 is an enlarged fragmentary vertical sectional view of the sheet feeding means of my present invention with the parts in the sheet feeding position as shown in Figure 3.

Referring now to Figures 1 and 3, I have shown a printing press having an upper main frame comprising a pair of spaced side walls I and 8 supported on a base structure formed in part by similarly spaced side walls I and 8. A plate and platen cylinder 9 of known construction is mounted between the side walls on a shaft I3 which extends between and is supported at its opposite ends for rotation in suitable bearings I2 and I3 carried by the side walls 1 and 8, re-

spectively.

The plate and platen cylinder as is known comprises a plate segment I4 and a platen segment I5, each of a circumferential extent of slightly less than half of the circumferential extent of the cylinder 9 with the plate segment I4, as is known, providing for the support thereon of a lithographic plate, or the like.

A blanket cylinder I6 as best shown in Figures l and 5 is disposed substantially immediately above the plate and platen cylinder 9 and it is carried by a shaft I1 which extends between the side walls I and 8 and is suitably journalled at its opposite ends therein. The blanket cylin der I6 carries a transfer blanket I8 of rubber or the like.

The plate and platen cylinder 3 and the blanket cylinder I5 as embodied in the press are well known in the art, and it is believed a further detailed description of these cylinders is not essential for an understanding of my present invention. The constructions of these two cylinders may vary widely and the only essential requirement is that such cylinders be of a character to provide a printing couple for printing a sheet as will hereafter appear. As previously referred to, the plate and platen cylinder 9 is of twice the diameter of the blanket cylinder I6 so that for each complete revolution of the plate I and platen cylinder 9, the blanket cylinder is rotated twice. The plate segment of cylinder 9, together with the lithographic plate carried thereby and the blanket I8 of the blanket cylinder I6, form a printing couple in a known manner. In the rotation of the plate and platen cylinder 9 in a counterclockwise direction, as indicated by the arrow in Figure l, the plate carried by the plate segment is adapted to be dampened by a suitable dampening means indicated generally at 20, and then inked by a suitable inking means indicated generally at 22. Upon rotation of the printing plate with the blanket cylinder, the ink image of the plate is transferred to the blanket I8 carried by the blanket cylinder I6. Upon feeding of a sheet between the printing couple formed by the blanket I8 of the blanket cylinder I6 and the impression or platen surface of the platen segment I5 the ink image on the blanket is transferred to the sheet. Thus, for each full revolution of the plate and platen cylinder 9 and two full revolutions of the blanket cylinder I6, the lithographic plate carried by the plate segment, is caused to be dampened and inked for transferring an ink image t the blanket I 8 of the blanket cylinder I6, and the ink image transferred from the lithographic plate to the blanket I8 of the blanking cylinder I5 is transferred to a sheet fed between the printing couple formed by the blanket I8 and the platen segment I5. The dampening and inking means include suitably lift off rolls as is known for engagement with cam means 23 for the platen segment to raise the form rolls off of the platen surface to prevent smearing of the latter.

The press further comprises a suitable form of drive means for rotating theprinting'cylinders and this drive means, as diagrammatically illustrated in Figure 1, comprises an electric motor 24 supported on brackets 25 extending between the side walls I' and 8' of the base of the press adjacent the lower end thereof. The armature shaft of the motor carries a pulley 26 for driving a belt 21, which in turn drives a pulley 28 fixed to a shaft 29 extending between the side walls 'I and 8' of the base. As best shown in Figure 5, the shaft 29 carries a gear 30 which has meshing engagement with a gear 32 carried by a shaft 33 disposed above the shaft 29 and journalled at its opposite ends in the side walls 'I' and 8' of the base. The shaft 33 at the end portion thereof adjacent the side wall I carries a gear 34 which has meshing engagement with a gear 35 carried by a shaft 36 which is suitably mounted at its opposite ends in the upper main frame side walls I and 8. The gear 35 has meshing engagement with an end gear 36 fixed to the shaft III for the plate and platen cylinder 9, and the gear 36 has meshing engagement with an end gear 31 fixed to shaft I! which carries the blanket cylinder IS. The driving means described thus provides for driving of the plate and platen cylinder 8 and the blanket cylinder IS in a known conventional manner. The arrangement is such that upon energization of the motor 24 the plate and platen cylinder and the blanket cylinder I6 are caused to be continuously rotated.

In the press, in which my present invention has been embodied, the plate and platen cylinder 9 carries a suitable sheet gripping means, which may be of known construction, and is indicated generally at 40 in Figures 2, 3 and 6. The sheet gripping means 40 is disposed to extend across the leading edge of the platen segment I5 and comprises a shaft 42 carrying, as shown in Figure 4, a plurality of movable gripping fingers 43 which are adapted to clamp the leading edge of a sheet to a grip bar 44. Suitable coil spring members 45 are carried by shaft 42 and engage the movable fingers 43 to dispose them normally to closed position with respect to the grip bar 44. As most clearly shown in Figures 5 and 6, the shaft 42 at the end thereof projecting toward the side wall 8 carries a crank arm 46 to the outer end of which a cam follower 41 is secured. A cam 48 is mounted inwardly of side wall 8 in a conventional manner, and the cam 48 when engaged by follower 41 effects opening of the gripper unit by movement of gripping fingers 43 away from the grip bar 44 against the force of springs 45 in proper timed sequence in the operation of the press to receive a sheet fed thereto by feed roll means of my present invention to be described hereafter and indicated generally at 49.

A second cam 50, as shown in Figures 2, 3 and 4, provides for opening of the sheet gripping unit 40 in position for discharging a, printed sheet from the press.

The sheet gripping means 48, above described. is representative of known mechanism movable with a printing cylinder for effecting registra- ;tion and printing of a sheet. The gripipng fingers 49 are normally biased to closed position and are moved to open position as by the cam 48 to receive a sheet and after passing the cam 48 close upon the leading edge of the sheet. The gripper means 46 is then subsequently opened by means of the cam 58 to effect discharge of the sheet after it has been printed.

The printing press, as best shown in Figures 1 and 4, further comprises a sheet feeding table indicated generally at 52 upon which sheets to be printed may be supported for hand feeding to the feed roll means indicated generally at 49. The sheet feeding table 52 is pivotally mounted as indicated at 53 on the outer side of the side wall I of the press so that it may be conveniently swung out of position in servicing of the press.

The press further comprises a sheet catcher indicated generally at 54 which is suitably detachably mounted on the side walls of the press rearwardly thereof and in a position to receive the printed sheets. The catcher 54 may be detachably mounted in any suitable manner so that it may be conveniently removed to provide for the ready servicing of the press from the rear thereof.

The sheet feeding table 52 comprises a horizontally disposed sheet supporting surface 55. which in the operation position of the sheet feeding table 52, is in alignment with a main sheet supporting or guide plate 56 which, as best shown in Figure 6, is provided with downwardly extending ears through which suitable bolts extend for mounting the plate 56 to extend transversely between the side walls 1 and 8 of the press. An auxiliary paper guide plate member 59 is disposed above the main paper guide plate 56 and projects inwardly toward the printing couple. The plate 59 with plate 56 forms a throat for directing the leading edge of a sheet to be printed to the open gripping unit 46. The auxiliary paper guide plate 59 as shown, is provided with end gears 62 which are suitably secured to the upwardly extending ears 63 disposed forwardly of and at opposite ends of the main plate 56.

The previously referred to sheet catcher 54, as best shown in Figures 2 and 3, also has embodied therewith a stripper member 86, and suitable ejector rolls, such as shown at 61, are also provided to enable the convenient stripping of a sheet from the platen segment upon opening of the gripper unit in the discharge of the printed sheet to the collector pan or catcher 54.

The above described elements of the printing press may be of known constructions and may vary widely in the adaptation of my present invention to a press embodying such elements. It is in such a relationship of parts for a printing press that I propose to embody the novel feed roll means indicated generally at 49 providing for the convenient use of the press for hand feeding of sheets thereto, and which sheets are subsequently fed by the feed roll means 49 to the open gripper unit 46 carried bythe plate and platen cylinder in proper timed sequence.

- Upon reference now, more particularly to Figures 2, 3 and 4, it will be observed that the feed roll means 49 of my present invention comprises an upper feed roll means indicated generally at II and a lower idler feed roll means indicated generally at I2. The upper feed roll means I8 comprises a shaft 19 having a plurality of friction feed rollers 14 fixed in longitudinally spaced relation on the shaft. The several rollers 14 are preferably made of rubber or other suitable composition of good friction characteristics so that when engaged with a sheet they are effective for advancing the sheet. The shaft 13 at its opposite ends is journalled in a frame or cradle 16 provided with offset end bosses TI into which studs I8 supported by the side walls 1 and 8 extend to provide a pivotal mounting for the frame or cradle 18.

The lower idler feed roll means 12 is disposed below the upper feed roll means I4 and comprises a shaft 88 suitably journalled at its opposite ends in the side walls 1 and 8. The shaft 88 carries a plurality of friction rollers 82 arranged in the same spaced relation as the friction rollers 14 of the upper feed roll means 10. The main paper supporting or guide plate 56 is provided with suitable spaced openings therein through which the friction rollers 82 of the lower idler feed roll means 12 project and which lower feed rollers 82 are adapted to engage frictionally the bottom surface of a sheet. Upon movement of the upper feed roller means 18 toward the lower idler feed roll means in a position to engage a sheet therebetween, the upper feed rollers 14 upon rotation of the upper feed roller shaft 19, in a manner to be described, and the lower feed rollers 82 provide for driving a sheet toward the printing press to the open gripper unit 48 as in the position of the parts shown in Figure 6.

The upper feed roll frame or cradle 16, as best shown in Figures 2, 3 and 4, is provided with a boss 82' to which is pivotally connected one end of a feed roll drive link 89. The other end of the drive link 83 is pivotally connected as at 84 adjacent the outer end of an arm 85 of a bell crank 86 pivotally supported on a stud 81 carried by the side wall 1 of the press. The other arm 88 of the bell crank carries a cam follower 89 which is adapted to have engagement with a feed roll drop cam 90 fixed to the shaft l0 carrying the plate and platen cylinder 9. A coil spring 92 has one looped end thereof disposed about a pin 93 fixed to the drive link 83 and its other looped end hooked to a pin 94 carried by the side wall 1 of the press. The spring 92 normally tends to bias the upper feed roll frame or cradle 10 in a counterclockwise direction as viewed in Figures 2 and 3, on studs 18 and the bell crank 86 in the like direction about stud 81 for engaging the follower 89 with the periphery of the upper feed roll cam 98. The feed roll cam drop 98 is provided with an inwardly sloping cam portion 95 which is adapted to be engaged by the cam follower 89 in the rotation of the plate and platen cylinder ill. The spring 92 in effecting counterclockwise rotation of the bell crank 86 to engage the cam follower 89 with the cam surface 95 also effects counterclockwise rotation of the upper feed roll frame or cradle 16 from its inoperative position shown in Figure 2 to its operative sheet driving position with respect to the lower idler feed roll means 12 as shown in Figure 3. The feed roll drop cam 90 is provided with outwardly sloping cam surface 96 which, when engaged by the cam follower 89, effects through the bell crank 86 and the drive link 92 limited rotation of the upper feed roll frame or cradle 10 in a clockwise direction from its operative position, shown in Figure 3, to its inoperative position, shown in Figure 2, against the force of spring 92.

The feed roll drop cam 90 is secured in appropriate position on the main shaft I for the plate and platen cylinder 9 so that in the rotation of the cylinders of the press, the upper feed roll means is caused to be moved in appropriate timed sequence to its operative sheet drive position, and to be rotated when disposed in its operative position, by means to be presently described, to drive a sheet disposed between the upper and lower feed rolls into the open gripper unit 40 as the leading edge of the platen segment approaches the blanket cylinder for aligning and registering the sheet in the open gripper for subsequent passage through the printing couple of the press. After the sheet has been fed into the open gripper unit 40, the outwardly sloping cam 95 of the feed roll drop cam 90 rocksthe upper feed roll means I0 to its non-driving or inoperative position shown in Figure 2. The mechanism above described, thus provides for disposing the upper feed roll means III to its operativeand inoperative positions in proper timed relation with respect to operation of the press.

Referring now more particularly to Figures 2, 3 and 5, it will be observed that the upper feed roll shaft I3 at the end thereof, inwardly of the side wall I of the press carries a pinion 98.. A drive rack 99 having meshing engagement with the pinion 98 is carried at one end of a connecting link I00 pivoted at I02 to the outer end of a crank arm I03. The crank arm I03 is pivoted at its other end as at I04 to a stud carried by the side wall I of the press. The crank arm I03 intermediate its ends carries a cam follower I05 which is adapted to have engagement with the periphery of an upper feed roll drive cam I06 which is secured to the feed roll drop cam 90. The upper feed roll drive cam I06 is provided with a plurality of arcuate slots I0'I through which threaded bolts I08 having threaded engagement with the feed roll drop cam 90 extend. The slots I01 and bolts I08 provide for adjusting the position of the feed roll drive cam I06 with respect to the feed roll drop cam 90. A drive rack guide indicated at H0 is journalled at the end of the shaft I3 of the upper feed roll means I0 inwardly of the side wall I, with the upper end portion of the drive rack guide being of channel shape to provide for retaining the rack bar in engagement with the pinion 98 secured to the end of the shaft I3. The feed roll drive cam I06 is provided with a cam surface II2 which is adapted when engaged by the follower I06 to rotate the crank arm I03 in a clockwise direction about its pivotal mounting I04 against the force of spring II5 biasing the follower I05 into engagement with the periphery of cam I06 to advance the drive rack in a direction to rotate the pinion 98, shaft I3, and upper feed rollers I4 in a clockwise direction. The relationship of the feed roll drop cam 90 and the feed roll drive cam I06 is such that as the cam 90 permits disposal, by spring 92, of the upper feed roll means I0 to its operative sheet driving position, the feed roll drive cam I06 drives the rack bar 99 which effects rotation of the upper feed roll means I0 so that the latter and the lower idler feed roll means I2 drive a sheet into the open gripper 40 in its sheet receiving position.

The coil spring I I5 is mounted at one end about a pin II6 carried by the crank arm I03 and at its other end to a pin III fixed to the side wall I of the frame of the press so that the spring H5 is operative to bias the crank arm I03 for movement in a counterclockwise direction about its pivot I04 to maintain the cam I05 in engagement with the feed roll drive cam I06. The outer upper end of the frame or cradle means I0, as shown, is provided at one end with an upwardly extending lug I30 which carries an adjustable set screw I32 adapted to have engagement with a cross bar I33 extending between the side walls I and 8 of-the press to limit the inward rocking movement of the upper feed roll means I0 toward the lower idler feed roll means I2 to control the biasing force of the spring 92 in frictionally enaging the sheet between the upper feed rollers I4 and the lower feed rollers 82.

Referring now more particularly to Figures 2 and 5, it will be observed that the upper feed roll means III also is provided with a plurality of stop fingers I20 fixed to the shaft I3 for movement therewith. The stop fingers I20 are arranged so that in the inoperative sheet driving position of the upper feed roll means I0 as shown in Figure 2, the fingers project downwardly and are disposed in the path of travel of a sheet toward the printing couple of the press. When the stop fingers I20 are in this position, the operator may manually position a sheet thereagainst, and in which position, upon movement of the frame or cradle I6 from its inoperative to operative sheet driving position, and upon rotation of the shaft I3, the stop fingers I20 are rotated with the shaft I3 moving the fingers to an inoperative position or position out of the path of travel of the sheet toward the printing couple. When the plate and platen cylinder 9 has rotated so that the inwardly sloping portion I25 of the feed roll drive cam I96 is engaged by the follower I05 of crank arm I03, the drive. rack 99 is drawn by means of spring II5 from the position thereof shown in Figure 3, to the position illustrated in Figure 2 which effects rotation of the upper feed roll means in a counterclockwise direction to restore it to its initial position for the next succeeding feeding operation. However, before the follower I05 engages the inwardly sloping surface I25 of the feed roll drive cam I06, the feed roll drop cam has effected movement of the frame or cradle I6 for the upper feed roll means I0 to its inoperative position.

The main paper guide plate 56 as best shown in Figure 6, is provided with a plurality of openings I35 into which one each of the stop fingers I20 project when the upper feed roll means I0 is disposed in its inoperative sheet driving position. Also the auxiliary paper guide plate 59 is provided with slots I36 at its forward edge to permit free movement of the stop fingers into and out of the path of travel of a sheet toward the printing couple. The auxiliary guide plate further along its rear edge is provided with slots I31 for permitting movement of the gripper fingers 43 to open position to receive a sheet from sheet feeding means 48 in the cycle of operation as above described.

It will be observed that in a press having the above described cycle of operation, an interval is provided following printing of a sheet and during the transfer of an ink image on the lithographic plate to the blanket cylinder for the operator to dispose the next sheet to be printed against the stop fingers I20 of the upper feed roll means I0 when the latter is disposed in its inoperative sheet driving position as shown in Figure 2. After placing of a sheet by the operator in this position, the upper feed roll means I0 is disposed to its operative sheet driving position to engage frictionally the sheet with the lower 9 feed roller means 12, after which the sheet is fed by the feed roll means 48 to the gripper unit 40 which is opened in proper timed sequence by the gripper opening cam 48.

The printing press of my present invention thus provides for the arrangement of a sheet feeding means for feeding sheets into a gripper unit carried by one of the printing cylinders in the opening or space provided at the front of the machine above the lower large plate and platen cylinder and close to the upper blanket cylinder. Such disposition of the feeding means provides a compact arrangement and additionally enables the convenient manual feeding of sheets to the press.

The press of my invention may be operated continuously with the appropriate hand feeding of the sheets as described being attended to by the operator during the cycle of operation of the press when the stop fingers I20 of the upper feed roll means are disposed in the path of travel of a sheet toward the printing couple.

While I have shown and described what I consider to be a preferred embodiment of my invention, it will be understood that various modifications and rearrangements may be made therein without departing from the spirit and scope of my invention.

'1 claim:

1. In a printing press having a pair of printing cylinders forming a printing couple, the combination of feed roll means for feeding a sheet toward said printing couple comprising lower idler feed roll means, and upper feed roll means, pivotally mounted frame means for rotatably supporting said upper feed roll means above said lower feed roll means, rocking means for rocking said frame in timed sequence with rotation of one of said printing cylinders for moving said upper feed roll means into operative and inoperative sheet driving positions with respect to said lower feed roll means, stop finger means mounted on said upper feed roll means for rotation therewith, said stop finger means being disposed in the path of travel of a sheet toward said printing couple in the said inoperative position of said upper feed roll means, and drive means between one of said printing cylinders and said upper feed roll means operable upon actuation of said rocking means disposing said upper feed roll means to its operative sheet driving position with respect to said lower feed roll means to rotate said upper feed roll means, and said upper feed roll means upon rotation thereof disposing said stop finger means to a position out of the path of travel of the sheet, whereby the sheet between said feed roll means is caused to be fed toward said printing couple.

2. In a printing press having a pair of printing cylinders forming a printing couple, the combination of feed roll means for feeding a sheet toward said printing couple comprising, lower idler feed roll means, and upper feed roll means, pivotally mounted frame means for rotatably supporting said upper feed roll means above said lower feed roll means, rocking means including a cam rotatable with one of said cylinders for rocking said frame means to move said upper feed roll means to operative and inoperative sheet driving positions with respect to said lower feed roll means, stop finger means mounted on said upper feed roll means for rotation therewith, said stop finger means being disposed in the path of travel of a sheet toward said printing couple in the said inoperative position of said upper feed roll means, and drive means including a cam rotatable with one of said cylinders operable upon actuation of said rocking means disposing said upper feed roll means to its operative sheetdriving position with respect to said lower feed roll means to rotate said upper feed roll means, and said upper feed roll means upon rotation thereof disposing said stop finger means to a position out of the path of travel of the sheet, whereby the sheet between said feed roll means is caused to be fed toward said printing couple.

3. In a printing press having a pair of printing cylinders forming a printing couple, the combination of feed roll means for feeding a sheet toward said printing couple comprising, lower idler feed roll means, and upper feed roll means, pivotally mounted frame means for rotatably supporting said upper feed roll means above said lower feed roll means, rc (:king means including a cam rotatable with one of said cylinders for rocking said frame means to move said upper feed roli means to operative and inoperative sheet driving positions with respect to said lower feed roll means, stop finger means mounted on said upper feed roll means for rotation therewith, said stop finger means being disposed in the path of travel of a sheet toward said printing couple in the said inoperative position of said upper feed roll means, and drive means including a pinion fixed to said upper feed roll means, a drive rack meshing with said pinion, and means including a cam rotatable with one of said cylinders for causing said rack to rotate said pinion, said drive means being operable upon actuation of said rocking means disposing said upper feed roll means to its operative position to effect rotation of the latter, whereby said stop finger means is rotated to a position out of the path of travel of the sheet and the sheet between said feed roll means is fed toward said printing couple.

4. In a printing press having a pair of printing cylinders forming a printing couple, the combination of sheet gripping means carried by one of said cylinders for rotation therewith, feed roll means for feeding a sheet toward said printing couple and into said sheet gripping means comprising, lower feed roll means, and upper feed roll means, pivotally mounted frame means rotatably supporting said upper feed roll means above said lower feed roll means, rocking means for rocking said frame in timed sequence with rotation of one of said printing cylinders to move said upper feed roll means into operative and inoperative sheet driving positions with respect to said lower feed roll means, stop finger means mounted on said upper feed roll means for rotation therewith, said stop finger means being disposed in the path of travel of a sheet toward said printing couple in the said inoperative position of said upper feed roll means, drive means between one of said printing cylinders and said upper feed roll means operable upon actuation of said rocking means disposing said upper feed roll means to its operative sheet driving position with respect to said lower feed roll means to rotate said upper feed roll means, and said upper feed roll means upon rotation thereof disposing said stop finger means to a position out of the path of travel of the sheet, whereby the sheet between said feed roll means is caused to be fed toward said printing couple, and means for opening said gripper means to receive the sheet from said feed roll means in timed sequence with the operation of the latter.

5. In a printing press having a pair of printlng cylinders forming a printing couple, the combination of feed roll means including lower feed roll means and an upper feed roll means, pivotally mounted frame means for rotatably supporting said upper feed roll means above said lower feed roll means for movement toward and away from the latter to operative and inoperative sheet driving positions with respect thereto, rocking means for rocking said frame means comprising a cam rotatable with one of said printing cylinders, a pivotally mounted bell crank having a follower on one of the arms thereof engaging said cam, a link pivotally connected at one end to the other arm of said bell crank and at its opposite end to said frame means, spring means for biasing said frame means in a direction for disposing said upper feed roll means to its operative position and said cam follower into engagement with said cam, said cam being operable for rotating said frame means against the force of said spring means to dispose said upper feed roller means to its inoperative position with respect to said lower feed roller means, and drive means for rotating said upper feed roll means comprising, a pinion carried thereby, a rack meshing with said pinion, a crank connected to said rack, a second cam rotatable with one of said cylinders, and a second cam follower carried by said crank for engagement with said second cam, and said second cam being operable to effect movement of said rack bar for rotating said pinion and said upper feed roll means when the latter is disposed in its operative position.

6. In a printing press having a pair of printing cylinders forming a printing couple, the combination of feed roll means including lower feed roll means and an upper feed roll means, pivotally mounted frame means for rotatably supporting said upper feed roll means above said lower feed roll means for movement toward and 12 away from the latter to operative and inoperative sheet driving positions with respect thereto, rocking means for rocking said frame means comprising a cam rotatable with one of said printing cylinders, a pivotally mounted bell crank having a follower on one of the arms thereof engaging said cam, a link pivotally connected at one end to the other arm of said bell crank and at its opposite end to said frame means, spring means for biasing said frame means in a direction for disposing said upper feed roll means to its operative position and said cam follower into engagement with said cam, said cam being operable for rotating said frame means against the force of said spring means to dispose said upper feed roller means to its inoperative position with respect to said lower feed roller means, and drive means for rotating said upper feed roll means comprising, a pinion carried thereby, a rack meshing with said pinion, a crank connected to said rack, a second cam rotatable with one of said cylinders, and a second cam follower carried by said crank for engagement with said second cam, and stop finger means rotatable with said upper feed roll means adapted in the inop erative position of the latter to be disposed in the path of movement of a sheet toward the printing couple, and in the operative position of said upper feed roll means to be rotated thereby to a position out of said path.

WILLIAM WARD DAVIDSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 497,745 Bascom May 16, 1893 1,307,969 Harris June 24, 1919 2,108,800 Davidson Feb. 22, 1938 2,246,508 Davidson June 24, 1941 

